X-Git-Url: https://git.lyx.org/gitweb/?a=blobdiff_plain;f=src%2FShareContainer.h;h=7fb74c79a0097befdf0db4f02b389507aa1a5a4c;hb=98c966c64594611e469313314abd1e59524adb4a;hp=2454e97f7a3235f428b62a85f4517fe9efb1f1ff;hpb=98336a5ee64d2900a5eabc3ea2c654a1ad3b571e;p=lyx.git diff --git a/src/ShareContainer.h b/src/ShareContainer.h index 2454e97f7a..7fb74c79a0 100644 --- a/src/ShareContainer.h +++ b/src/ShareContainer.h @@ -9,30 +9,27 @@ #include #include -/// +/// Share objects between several users. +/** + This class can be used to reduce memory consuption when you have a lot + of equal objects used all over your code. + + \author Lars Gullik Bjønnes +*/ template -class ShareContainer : public noncopyable { +class ShareContainer : boost::noncopyable { public: /// typedef std::vector > Params; /// typedef typename Params::value_type value_type; - /// + /// Return a shared_ptr that points to a element equal to ps. value_type get(Share const & ps) const { // First see if we already have this ps in the container -#if 0 - Params::iterator it = params.begin(); - Params::iterator end = params.end(); - for (; it != end; ++it) { - if (ps == *(*it).get()) - break; - } -#else Params::iterator it = std::find_if(params.begin(), - params.end(), - isEqual(ps)); -#endif + params.end(), + isEqual(ps)); value_type tmp; if (it == params.end()) { // ok we don't have it so we should @@ -43,15 +40,18 @@ public: // some (one) unique elemements some times // but we should gain a lot in speed. clean(); - std::sort(params.rbegin(), params.rend(), comp()); } else { // yes we have it already tmp = *it; + // move it forward - optimization + // makes the next find faster. + if (it != params.begin()) + std::swap(*it, *(it - 1)); } return tmp; } private: - /// + /// A functor returning true if the elements are equal. struct isEqual { isEqual(Share const & s) : p_(s) {} bool operator()(value_type const & p1) const { @@ -60,32 +60,26 @@ private: private: Share const & p_; }; - /// - struct comp { - int operator()(value_type const & p1, - value_type const & p2) const { - return p1.use_count() < p2.use_count(); - } - }; - /// + /// A functor returning true if the element is unique. struct isUnique { bool operator()(value_type const & p) const { return p.unique(); } }; - /// + /** Remove all unique items. + This removes all elements from params that is only referenced + from the private container. This can be considered a memory + optimizaton. + */ void clean() const { - // Remove all unique items. (i.e. entries that only - // exists in the conatainer and does not have a - // corresponding paragrah. Params::iterator it = std::remove_if(params.begin(), params.end(), isUnique()); params.erase(it, params.end()); } - - /// + + /// The actual container. mutable Params params; }; #endif